JPS6024545A - Positive photosensitive resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a positive photosensitive resin composition.

More specifically, the present invention relates to a positive photosensitive resin composition that is made from an alkali-soluble novolac resin and has extremely small striations after being spin-coated onto a substrate such as a silicon wafer.

Currently, the resist most commonly used for producing integrated circuits is a negative photoresist, which is a mixture of cyclized isoprene rubber and a bisazide compound. Although this type of photoresist is easy to use under extreme pressure, it has limited ability to resolve patterns and cannot keep up with the increasing density of integrated circuits over the years. Alkali-soluble novolak resin-based positive-working photoresists are about to replace this cyclized isoprene rubber-based negative-working photoresists.

Most of these positive photoresists are made by adding a 1,2-quinonediazide compound to an alkali-soluble novolac resin, and when irradiated with light, the 1,2-quinonediazide compound decomposes to produce carboxylic acid. We are using.

Furthermore, since an alkaline aqueous solution is used as the developer, swelling of the pattern during development is extremely small and high resolution can be achieved. However, compared to negative-tone photoresists based on cyclized isoprene rubber, there are drawbacks such as low sensitivity, poor adhesion to silicon wafers, and brittleness and easy cracking. Another drawback is that the surface becomes uneven, like waves. Despite these drawbacks, the use ratio of the positive photoresist is increasing solely because the positive photoresist has high resolution. The phenomenon described in (■) above is called "striation," but after the phenomenon, the striation may become even larger. If this striation is large, the dimensional accuracy of the resist pattern will be impaired, and there is a risk that the high resolution, which is an advantage of a positive photoresist, will be lost. However, none of the positive photoresists currently available on the market has a satisfactory level of striation.

The present inventors conducted extensive research to improve these drawbacks, and found that striations were improved by using a mixed solvent of organic solvents with different boiling points as a solvent for the above-mentioned positive photoresist. I made a mistake.

That is, the present invention uses an alkali-soluble novolac resin and a 1,2-quinonediazide compound with a boiling point of 60 to 17
An organic solvent (A) having a boiling point of 0C and an organic solvent (B) having a boiling point of 180 to 350C are prepared by (A)/(B)=50150 to
This is a positive photosensitive resin composition characterized by being dissolved in a mixed solvent mixed in a ratio of 99/1 (weight ratio).

Examples of the organic solvent (A) having a boiling point of 60 to 170 t:' used in the present invention include glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, and cellosolve esters such as methyl cellosolve acetate and ethyl cellosolve acetate. Examples include aromatic hydrocarbons such as toluene and xylene, ketones such as methyl ethyl ketone and cyclohexane, and esters such as ethyl acetate and butyl acetate. You can also do that. The preferred boiling point of the organic solvent (A) is 110 to 17
It is 0C.

Examples of the organic solvent (B) having a boiling point of 180 to 350 C include ethers such as benzyl ethyl ether, 1,2-dibutoxyethane, and dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol motsubutyl ether, and diethylene glycol. Glycol ethers such as diptyl ether, ketones such as acetonyl acetone, acetophenone, and isophorone, fatty acids such as caproic acid and caprylic acid, 1-octatool, 1-nonanol, 1-decanol, 1-dodecanol, benzyl alcohol, etc. Alcohols, 2-ethylhexylua 7f
-), hensyl acetate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, benzyl benzoate, diethyl oxalate, dibutyl oxalate, diethyl malonate, diptyl tartrate, dimethyl maleate, diethyl maleate, maleic acid. Examples include esters such as dipyl acid, dimethyl phthalate, ethylene carbonate, propylene monocarbonate, butyl cellosolve acetate, and phenyl cellosolve acetate.

Although the boiling point of the organic solvent (B) is in the range of 180 to 350 C, it is preferable to use an organic solvent (B) having a boiling point of 200 to 300 C. Moreover, two or more types of organic solvents (B) can also be used in combination.

The mixing ratio (A)/(B) of the organic solvent (A) and organic solvent (B) in the present invention is 50150 to 99/1 (weight ratio), preferably 70/30 to 9515 (weight ratio). It is. If the ratio of the organic solvent (B) exceeds 50, the organic solvent (B) will not evaporate sufficiently during the pre-baking process after applying the photosensitive resin composition onto a substrate such as a silicon wafer, and will not be absorbed into the photosensitive resin film. Since it remains, the surface of the photosensitive resin becomes sticky, causing sticking.

Furthermore, if a silicon wafer or the like having a silicon oxide film on the surface is used as a substrate, the pattern formed thereon may peel off during development and may reduce the heat resistance of the photosensitive resin. ) is less than 1,
The objective of the present invention, which is to improve the striations of the photosensitive resin composition, cannot be achieved.

The alkali-soluble novolac resin used in the present invention preferably contains phenols and aldehydes.
Produced by addition condensation of aldehydes under an acid catalyst at a ratio of 0.7 to 1 mole per mole. Phenols include phenol, 0-cresol, m-cresol, p-lusol, 0-ethylphenol, m-ethylphenol, p-ethylphenol, O-butylphenol, m-
Butylphenol, p-butylphenol, 2,3-xylenol, 2.4-xylenol, 2,5-xylenol, 2,6-xylenol, 3.4-xylenol,
Examples include 3,6-xylenol and p-phenylphenol. These phenols can be used alone or in combination of two or more, taking into consideration their alkali solubility. Also, examples of aldehydes include formaldehyde,
Examples include paraformaldehyde and furfural. As the acid catalyst, inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, and organic acids such as formic acid, oxalic acid, and acetic acid are used.

The 1,2-quinonediazide compound used in the present invention is
For example, 1,2-benzoquinonediazide sulfonic acid ester, 1,2-naphthoquinonediazide sulfonic acid ester, l,2-benzoquinonediazide sulfonic acid amide, 1
, 2-naphthoquinonediazide sulfonic acid amide, etc., and known 1,2-quinonediazide compounds can be used as they are. More specifically, J. Koaar
Author'"Light-5ensitive System
ms' 339-352.

(1965), John Wiley & 5on8
Company (New York), W, S, [)e Fo
``Photoresist'' 50 by rest, (1
975), Mc Graw-Hill, inc.
(New York). That is, 1,2-
Benzoquinonediazide-4-sulfonic acid phenyl ester, di(1'.

2'-Benzoquinonediazide-41-sulfonyl)-4
, 4'-dihydroxypiphenyl, 1,2-benzoquinonediazide-4-(N-ethyl-N-β-naphthyl)-
Sulfonamide, 1,2-naphthoquinonediazide-5-
Sulfonic acid cyclohexyl ester, 1-(1',2'
-naphthoquinonediazide-5'-sulfonyl)-3,5
-dimethylpyrazole, 1,2-naphthoquinonediazide-5-sulfonic acid-4'-hydroxydiphenyl-4'
-7zo β-naphthol ester, N,N-di(1゜2-naphthoquinonediazide-5-sulbonyl)-aniline, 2-(1',2'-naphthoquinonediazide-57-
sulfonyloxy)-1-hydroxyanthraquinone,
Condensate of 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 4.4'-diaminobenzophenone, 2 moles of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 4,4'-dihydroxy- 1,1'
- condensate of 1 mole of diphenylsulfone, condensate of 1 mole of 1,2-naphthoquinonediazide-5-sulfonic acid chloride and 1 mole of purbrogalin, 1,2-naphthoquinonediazide-5-(N-dihydroabiethyl)-sulfonamide etc. can be exemplified.

Also, 2,3.4-)dihydroxyphenyl-n-butylketone-1,2-naphthoquinonediazide-5-sulfonic acid monoester, 2,3.4-)dihydroxyphenyl-n-hexylketone-1,2-naphtho trihydroxyphenylalkylketone-1,2-naphthoquinonediazide-5-sulfonic acid monoesters such as quinonediazide-5-sulfonic acid monoester, 2,3.4-)
IJ Hydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid monoester, 314.5-
Trihydroxyphenylalkyl ketone-1,2-naphthoquinonediazide-5-sulfonic acid monoesters such as trihydroxybenzophenone-1゜2-naphthoquinonediazide-5-sulfonic acid monoester, 2.3.4-
) Lihydroxyphenylbenzylketone-1,2-naphthoquinonediazide-5-sulfonic acid monoester, 3.
4.5-trihydroxyphenylbenzyl ketone-1,
trihydroxyphenylaralkyl ketone such as 2-naphthoquinonediazide-5-sulfonic acid monoester;
Z-naphthoquinone diazide-5-sulfonic acid monoesters and the like can also be exemplified.

In addition, the special public interest public interest public works shall be
-13109, 40-26126, 40-3801
, 45-5604, 45-27345, 51-1
3013, JP 48-96575, JP 48-6380
2, 48-63803 and the like can also be used.

Furthermore, Japanese Patent Application Publication No. 58-75149, Patent Application No. 57-6575
9, 58-40478 &C 1,2-quinonediazide compounds described in &C, i.e., 1,2-quinonediazide compounds represented by the following general formula (I), (wherein R1 to R are the same or different, hydrogen, alkyl group, alkoxy group, hydroxyl group or ti-OR?,
R6 is an alkyl group, an aryl group, an aralkyl group,
R1 is a 1,2-naphthoquinonediazide-4-sulfonyl group, a 1,2-naphthoquinonediazide-5-sulfonyl group, or a 1,2-benzoquinonediazide-4-sulfonyl group. Further, at least one of R3 to R3 is -OR, and the number of -0R does not exceed three. ) A 1,2-quinonediazide compound represented by the following general formula (II) and a 1,2-quinonediazide compound represented by the following general formula (Ill)
The quinonediazide compound was mixed in a ratio of 1 to 9:9 to 1 (Mo.

A mixture of 1,2-quinonediazide mixed in a ratio of % R,, R,
and ntt are the same or different, 1,2-naphthoquinonediazide-4-sulfonyl group, 1,2-su7toquinonediazide-5-sulfonyl group, 1,2-benzoquinone-4
7 Al with sulfonyl group. ) A 1,2-quinonediazide compound represented by the following general formula (IV) and a 1,2-quinonediazide compound represented by the following general formula (V
), the 1゜2-quinonediazide compound represented by 6 to 9
: 1,2-quinonediazide mixture mixed at a ratio of 4 to 1 (molar ratio), 0R16 H (wherein R13 and R17 are the same or different and are an alkyl group, an aryl group or an acid aralkyl group, R,,
, R, R86, R18 and R1° are the same or different, a 1,2-naphthoquinonediazide-4-sulfonyl group, a 1,2-naphthoquinonediazide-5-sulfonyl group or a 1,2-benzoquinonediazide-4-sulfonyl group It is. ) can also be mentioned.

Examples of the 1,2-quinonediazide compound represented by the above general formula (I) include nonyl m-hydroxybenzoate.
1,2-naphthoquinonediazide-5-sulfonic acid ester, m-hydroxybenzoic acid lauryl-1,2-naphthoquinonediazide-5-sulfonic acid ester, p-hydroxybenzoic acid nonyl-1,2-naphthoquinonediazide
5-sulfonic acid ester, p-hydroxybenzoic acid lauryl-1,2-su7toquinonediazide 5-sulfonic acid ester, p-hydroxybenzoic acid phenyl-1,2'
-Naphthoquinonediazide-5-sulfonic acid ester Cape hydroxybenzoic acid ester-1,2-naphthoquinonediazide-5-sulfonic acid ester! , 3.5-dihydroxybenzoic acid lauryl-1,2-naphthoquinonediazide-5-sulfonic acid diester, 3. phenyl-1,2-naphthoquinonediazide-5 s-dihydroxybenzoate
- Dihydroxybenzoic acid esters such as sulfonic acid diesters -1,2-naphthoquinonediazide-5-sulfonic acid esters, 2,3゜4-trihydroxybenzoic acid lauryl-1,2-naphthoquinonediazide-5-sulfonic acid diesters, 2,3.4-) lauryl-1,2-su7toquinonediazide 5-sulfonic acid triester, 2,3.4- phenyl-1,2-naphthoquinonediazide-5-trihydroxybenzoate Sulfonic acid diester, trihydroxybenzoic acid ester-1,2-nafdoquinonediazide-5-sulfonic acid ester such as 2,3.4-trihydroxybenzoic acid phenyl-1,2-naphthoquinonediazide-5-sulfonic acid triester The following examples can be given.

Examples of the 1,2-quinonediazide compound represented by the above general formula (II) include 2,4-dihydroxyphenylmethylketone-1,2-naphthoquinonediazide-5-sulfonic acid monoester, 2,4-dihydroxyphenylbutylketone- 1,2-naphthoquinonediazide-5-sulfonic acid monoester, 2,4-dihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid monoester, 3,4-dihydroxybenzophenone-1
゜2-Naphthoquinonediazide-5-sulfonic acid monoester, 2,4-dihydroxyphenylbenzyl ketone-
Dihydroxyphenylalkyl ketone-1, such as 1,2-naphthoquinonediazide-5-sulfonic acid monoester,
2-naphthoquinone diazide-5-sulfonic acid monoesters, dihydroxyphenylaryl ketone-1,2-
Examples include naphthoquinonediazide-5-sulfonic acid monoesters and dihydroxyphenylaralkyl ketone-1,2-naphthoquinonediazide-5-sulfonic acid monoesters.

Examples of the 1,2-quinonediazide compound represented by the above general formula (m) include 2,4-dihydroxyphenylmethylketone-1,2-naphthoquinonediazide-5-sulfonic acid diester, 2,4-dihydroxyphenylbutylketone-1 , 2-naphthoquinonediazide-5-sulfonic acid diester, 2゜4-dihydroxybenzophenone-1,
2-naphthoquinonediazide-5-sulfonic acid diester, 3,4-dihydroxybenzophenone-1,2-1-
Atoquinonediazide-5-sulfonic acid geste”s
2v 4-dihydroxyphenylbenzylketone-
Dihydroxyphenylalkyl ketone-1,2 such as 1,2-naphthoquinone diazide-5-sulfonic acid diester
- Naphthoquinonediazide-5-sulfonic acid diesters, dihydroxyphenylarylketone-1,2-naphthoquinonediazide-5-sulfonic acid diesters, dihydroxyphenylaralkyl ketone-1,2-naphthoquinonediazide-5-sulfonic acid diesters are exemplified. @ As the 1,2-quinonediazide compound represented by the above general formula (■), 2,3.4-)lyhydroxyphenyl-n-butylketone-1,2-naphthoquinonediazide-5
-Sulfonic acid triester, 2.3.4-) Lihydroxyphenyl-n-hexyl ketone-1,2-naphthoquinone diazide-5-Trihydroxyphenylalkyl ketone of sulfonic acid triester group -1,2-naphthoquinone diazide- 5-sulfonic acid triesters, 2゜3.
4-trihydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid triester, 3,4
, 5-trihydroxyphenylarylketone-1,2-naphthoquinonediazide-5-sulfonic acid triesters such as 5-trihydroxybenzophenol-1,2-naphthoquinonediazide-5-sulfonic acid triester, 2
, 3.4-) 'J H)' Roxyphenylbenzylketone-1,2-naphthoquinonediazide-5-sulfonic acid triester, 3.4.5-)dihydroxyphenylbenzylketone-1,2-naphthoquinonediazide-5 Examples include trihydroxyphenylaralkyl ketone-1,2-naphthoquinonediazide-5-sulfonic acid triesters such as -sulfonic acid triesters.

As the 1,2-quinonediazide compound represented by the above general formula (V), 2,3.4-)"dihydroxyphenyl-n-butylketone-1,2-naphthoquinonediazide-
Trihydroxyphenylalkyl ketone-1,2-naphthoquinonediazide-5 such as 5-sulfonic acid diester, 2.3.4-)lihydroxyphenyl-n-hexylketone-1,2-naphthoquinonediazide-5-sulfonic acid diester -Sulfonic acid diesters, 2,3゜4-
Trihydrogenoxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid diester, 3,4.5-)
Trihydroxyphenylarylketone such as hydroxybenzophenone-1,2-naphthoquinonediazide-5-sulfonic acid diester, 1,2-naphthoquinonediazide-5-sulfonic acid diester, 2,3.4-trihydroxyphenylbenzyl ketone 1,2-naphthoquinonediazide-5-sulfonic acid diester, 31415-
Examples include trihydroxyphenylaralkylketone-1,2-naphthoquinonediazide-5-sulfonic acid diesters such as IJ hydroxyphenylbenzylketone-1'-112-naphthoquinonediazide-5-sulfonic acid diesters.

Of course, the above general formula (I), general formula (U), general formula (m
), 1 represented by general formula (IV) or general formula (V),
Each of the 2-naphthoquinonediazide compounds can be used alone.

The amount of these 1,2-quinonediazide compounds added is preferably 5 to 10 parts by weight, particularly preferably 1 to 5 parts by weight, per 100 parts by weight of the alkali-soluble novolac resin.
It is 0 parts by weight. If the amount is less than 5 parts by weight, the amount of carboxylic acid produced by absorbing light is small, so it is impossible to make a difference in the solubility of the ridge before light irradiation in a developer consisting of an alkaline aqueous solution as a photosensitive resin coating. Buttering becomes difficult. If the amount exceeds 100 parts by weight, most of the added 1,2-quinonediazide compound will still remain in the same form after short-time light irradiation, and the insolubilization effect in the alkaline aqueous solution will be too high, making it difficult to develop the photosensitive resin coating. In addition, the coating film forming ability and mechanical properties of the coating film decrease. Further, depending on the type of l,2-quinonediazide compound, the developability of the coating film of the photosensitive resin composition of the present invention in a developer consisting of an alkaline aqueous solution, the adhesiveness to a substrate, etc. can be changed.

In the photosensitive resin composition of the present invention, the alkali-soluble novolac resin and the 1,2-quinonediazide compound are mixed in an organic solvent (A) and an organic solvent (B) in the following manner: (A)/(B) = 5
0150 to 99/1 (weight ratio) in a mixed solvent. The amount of this mixed solvent to be used is preferably 50 to 90% by weight of the photosensitive resin composition, and in this amount, the thickness of the coating film will vary depending on the method of coating the photosensitive resin composition on the substrate. It is easy to adjust the thickness within 0.2 to 10 μm.

Further, a surfactant can be added to the photosensitive resin composition of the present invention in order to improve developability and dimensional stability of a pattern.

Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol, etc. Examples include polyoxyethylene alkylphenol ethers, polyethylene glycol dialkyl esters such as polyethylene glycol dilaurate, and polyethylene glycol distearate.

Furthermore, storage stabilizers, dyes, pigments, etc. can be added to the photosensitive resin composition of the present invention as required. Also, the coating film of the photosensitive resin composition of the present invention and the silicon oxide film etc. In order to improve the adhesion to the substrate, hexamethyldisilazane, chloromethylsilane, or the like can be applied to the substrate in advance.

After applying and drying the photosensitive resin composition of the present invention, the developer of the coating film exposed through a pattern mask includes sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, Inorganic alkalis such as aqueous ammonia, primary amines such as ethylamine and n-propylamine, tertiary amines such as diethylamine and di-n-propylamine, tertiary amines such as triethylamine and methyldiethylamine, dimethylethanolamine , alcohol amines such as triethanolamine, aqueous solutions of alkalis such as quaternary ammonium salts such as tetramethylammonium hydroxide and -ytraethylammonium hydroxide, pyrrole, piperidine, 1,8
-diazabicyclo(5,4,0)-7-undecene, 1
, 5-diazabicyclo(4,3,0)-5-nonane and other cyclic amines are used, and when manufacturing integrated circuits, where the use of metal-containing developers becomes a problem, quaternary ammonium salts and cyclic amines are used. Preference is given to using aqueous solutions of amines.

Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as an alcohol such as methanol or ethanol or a surfactant to the aqueous solution of the alkali mentioned above can also be used as the developer.

The photosensitive resin composition of the present invention is particularly useful not only as a positive photoresist for producing integrated circuits, but also as a positive photoresist for producing masks.

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by these Examples.

In addition, the organic solvent (A) and the organic solvent (
The boiling point of B) indicates the boiling point at 1 atmosphere.

Example 1 Three-piece separable flask with an internal volume of 500 tnl kCm
- After adding 75% of cresol and 25% of p-cresol, 37% by weight formalin aqueous solution 50+tA', oxalic acid 0
．． 049 was added. While stirring, the separable flask was immersed in an oil bath, the reaction temperature was controlled at 100 °C, and the reaction was allowed to proceed for 10 hours, thereby synthesizing a novolac resin from K. After the reaction, water was removed by reducing the pressure to 30 mH9,
Furthermore, the internal temperature was raised by 130CK to remove unreacted substances. Then, the molten alkali-soluble novolac resin was returned to room temperature and recovered. The above-mentioned alkali-soluble novolak resin 4
．． 3g, 2.3.4-trihydroxybenzophenone-
1,2-naphthoquinonediazide-5-sulfonic acid trinis f-IO, 79 12 g of ethyl cellosolve acetate with a total boiling point of 156.3 C and 39 benzyl acetate with a boiling point of 213.50 [organic solvent (A)/organic solvent (B) = 80/20
(weight ratio)] with a pore size of 0.2μ.
A photosensitive resin composition was prepared by filtration through a membrane filter.

The photosensitive resin composition was coated with a spinner onto a silicon wafer having a silicon oxide film, and then brebaked in an oven at 100 C for 10 minutes to form a resist film with a thickness of 1 μm.

Surface shape measuring device (Rank Taylor Hopso: / Company Mdl)
When we measured the striations of a resist film applied to a silicon wafer using rc (restep), we found that the average was 2OA
A very small value was obtained. After applying a test pattern mask manufactured by Toppan Printing Co., Ltd. to the wafer and exposing it to ultraviolet light, the wafer was developed with an aqueous solution of tetramethylantinium hydroxide and rinsed with running water. When the striae after development was measured, the average value was 20A, which was the same as the value after coating.

Comparative Example 1 Streation was measured in the same manner as in Example 1 except that 15 g of ethyl cellosol acetate was used instead of the benzyl acetate of Example 1, and the striae was found to be a very large value of 210A. In addition, the striae at the development edge was quite thick and measured 35OA.

Examples 2 to 11 The striations were measured in the same manner as in Example 1, except that the organic solvent (B) shown in Table 1 was used in place of benzyl acetate in Example 1. The value was very small. The results are shown in Table-1.

Table-1 Examples 12 to 13 Streation was measured in the same manner as in Example 1, except that the mixing ratio of ethyl cellosolve acetate and benzyl acetate used in Example 1 was changed as shown in Table-2, and a total of 159 was used. However, all striations were at a satisfactory level of cloudiness. The results are shown in Table-2.

Table 2 ■ Comparative Example 2 The same procedure as in Example 1 was repeated except that the mixing ratio of ethyl cellosolve acetate and benzyl acetate used in Example 1 was changed to 40/60 and a total of 15 g was used, except that 1st needle and 1st needle were added. Since benzyl acetate remained in the resist layer and the resist surface was soft, the stylus did not work properly and measurement was impossible. It was also found that if the resist was brought into close contact with the test pattern mask, the resist would be damaged when the test pattern mask was removed, and would no longer function as a resist.

Claims (1)

[Claims] An alkali-soluble novolac resin and a 1,2-quinonediazide compound are mixed with an organic solvent (A) having a boiling point of 60 to 170G and an organic solvent (B) having a boiling point of 180 to 350C.
A positive photosensitive resin composition, characterized in that it is dissolved in a mixed solvent in which (A)/(B) = 50150 to 99/1 (weight ratio).